
/**
 * {

    "_id": "MqxQgEFhpH"
    "question_content": "werewrew"
    "question_id": "DSP7nm9hY7"
    "answer": "trewrrewrew"
    "answer_index": 1
    "is_correct": false
    "_p_createdBy": "_User$4Z6ZQcr9aI"
    "_created_at": "ISODate("2018-08-26T06:05:12.416Z")"
    "_updated_at": "ISODate("2018-08-26T06:05:12.416Z")"

}
 */
/**
 * 答案表，
 * 表名：answers
 */
const answers = {

    "_id": "答案id（系统字段）"
    , "question_content": "题目"
    , "question_id": "题目id"
    , "answer": "答案"
    , "answer_index": "答案索引"
    , "is_correct": "是否正确答案（false/true）"
    , "_p_createdBy": "创建者"
    , "_created_at": "创建时间(系统字段)"
    , "_updated_at": "更新时间(系统字段)"

}